unix: fix MremapPtr test failing on NetBSD

NetBSD apparently doesn't allow remapping into used address space.
This means that the test that uses mremap to move a mmapped page
into a new address should first mmap (to reserve)
then munmap (to free) the destination.

Fixes golang/go#68180

Change-Id: If66b67e7166ca4dc4331a8cfc3e3a285416e9849
GitHub-Last-Rev: 92058c2f25
GitHub-Pull-Request: golang/sys#198
Cq-Include-Trybots: luci.golang.try:x_sys-gotip-netbsd-amd64
Reviewed-on: https://go-review.googlesource.com/c/sys/+/594756
Reviewed-by: Ian Lance Taylor <iant@google.com>
Reviewed-by: Joedian Reid <joedian@google.com>
Auto-Submit: Dmitri Shuralyov <dmitshur@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
This commit is contained in:
Nuno Cruces
2024-06-26 13:57:46 +00:00
committed by Gopher Robot
parent daa239428c
commit a0ef40af1f

View File

@@ -47,30 +47,31 @@ func TestMremap(t *testing.T) {
}
func TestMremapPtr(t *testing.T) {
mmapProt := unix.PROT_NONE
mmapPtrProt := unix.PROT_READ | unix.PROT_WRITE
b, err := unix.Mmap(-1, 0, 2*unix.Getpagesize(), mmapProt, unix.MAP_ANON|unix.MAP_PRIVATE)
p1, err := unix.MmapPtr(-1, 0, nil, uintptr(2*unix.Getpagesize()),
unix.PROT_READ|unix.PROT_WRITE, unix.MAP_ANON|unix.MAP_PRIVATE)
if err != nil {
t.Fatalf("Mmap: %v", err)
}
if _, err := unix.MmapPtr(-1, 0, unsafe.Pointer(&b[0]), uintptr(unix.Getpagesize()),
mmapPtrProt, unix.MAP_ANON|unix.MAP_PRIVATE|unix.MAP_FIXED); err != nil {
t.Fatalf("MmapPtr: %v", err)
}
b[0] = 42
p2 := unsafe.Add(p1, unix.Getpagesize())
if err := unix.MunmapPtr(p2, uintptr(unix.Getpagesize())); err != nil {
t.Fatalf("MunmapPtr: %v", err)
}
*(*byte)(p1) = 42
if _, err := unix.MremapPtr(
unsafe.Pointer(&b[0]), uintptr(unix.Getpagesize()),
unsafe.Pointer(&b[unix.Getpagesize()]), uintptr(unix.Getpagesize()),
p1, uintptr(unix.Getpagesize()),
p2, uintptr(unix.Getpagesize()),
unix.MremapFixed|unix.MremapMaymove); err != nil {
t.Fatalf("MremapPtr: %v", err)
}
if got := b[unix.Getpagesize()]; got != 42 {
if got := *(*byte)(p2); got != 42 {
t.Errorf("got %d, want 42", got)
}
if err := unix.Munmap(b); err != nil {
t.Fatalf("Munmap: %v", err)
if err := unix.MunmapPtr(p2, uintptr(unix.Getpagesize())); err != nil {
t.Fatalf("MunmapPtr: %v", err)
}
}